1. Technical Field
Several aspects of the present invention relate to a micro electro mechanical device, a method for manufacturing the same, a semiconductor device, and a method for manufacturing the same.
2. Related Art
Development and application of a sensor using a micro electro mechanical system (MEMS) composed of minute components to which a fine processing technique is applied has drawn increasing attention.
A pressure sensor and an acceleration sensor are examples of the above mentioned sensor. A technique detecting pressure or the like by the change of the electrostatic capacitance between two electrodes are used in a first example of related art. JP-A-2006-126182 is the first example of related art.
A sensor using a field effect transistor (EFT) has been under development as described in a second example and a third example of related art. JP-A-2007-71846 is the second example of related art, while S. Buschnakowski, et. al., “Development and Characterization of a High Aspect Ratio Vertical FET Sensor for Motion Detection”, Transducers 2003, pp. 1391-1394 (2003) is the third example of related.
The inventor examines further the miniaturization and the performance improvement of sensors to which MEMS technique is applied.
However, the above mentioned sensor using the change of the electrostatic capacitance has a problem in that sensitivity is decreased due to the parasitic capacitance of wiring lines coupled to the sensor or the area of the electrode (for example, 300 μm to 500 μm square) is increased for enhancing the sensitivity.
On the contrary, downsizing and sensitivity enhancement can be achieved when the FET is used due to a signal amplification function of the FET.
However, the second and the third examples of related art have problems in that the steric structure is complicated and the manufacturing process is long and complicated.